Packaging machine

ABSTRACT

Apparatus and method are disclosed for vacuum packaging of a product in a two element package consisting of a preformed rigid base element and a preformed rigid cover element. The apparatus preferably includes a plurality of platens carried on a conveyor through a number of operating stations where the package is assembled with the base element disposed downwardly. The loosely assembled package is moved into sealing station where a concave housing placed over the package elements forms a vacuum chamber with the platen. The chamber is vacuumized, and an annular sealing member carried within the concavity of the housing moves downwardly to press the peripheral portions of the package elements together while a vacuum is maintained within the chamber.

United States Patent Rousseau et al.

[451 May 23, 1972 Primary ExaminerTravis S. McGehee Attorney-Pendleton,Neuman, Williams & Anderson [57] ABSTRACT Apparatus and method aredisclosed for vacuum packaging of a product in a two element packageconsisting of a preformed rigid base element and a preformed rigid coverelement. The apparatus preferably includes a plurality of platenscarried on a conveyor through a number of operating stations where thepackage is assembled with the base element disposed downwardly. Theloosely assembled package is moved into sealing station where a concavehousing placed over the package elements forms a vacuum chamber with theplaten. The chamber is vacuumized, and an annular sealing member carriedwithin the concavity of the housing moves downwardly to press theperipheral portions of the package elements together while a vacuum ismaintained within the chamber.

25 Claims, 19 Drawing Figures [54] PACKAGING MACHINE [72] Inventors: RoyS. Rousseau; Raymond J. Keating,

both of Bettendorf; Gary L. Steinke,

Davenport, all of Iowa [73] Assignee: The Kartridge-Pak Co., Davenport,Iowa [22] Filed: Nov. 24, 1969 [21] Appl. No.: 879,338

[52] U.S.Cl ..53/ll2R, 99/171 [51] Int. Cl ..B65b 31/02 [58]FieldofSearch ..53/ll2 R, 112A [56] References Cited UNITED STATESPATENTS 3,283,469 11/1966 McBracly et al ..53/1 12 A X 3,247,643 4/1066Bartelt ....53/1 12 A 3,340,668 9/1967 Bofinger ..53/1 12 X l I L illlhv l illh-ruu 1 5 I [F i m%\ 8 Sheets-Sheet 1 t Patented I May 23,1972 Patented May 123, 1972 3,664,085

8 Sheets-Sheet 2 Patented May 23, 1972 8 Sheets-Shout 4 Patented May 23,1972 s Shets-Sheet 6,015,319 y) 6568 wee 0Q mmw %W\ ew %\W W Gm N0\ \mW\Patented 'May 23, 1972 '8 Sheets-Sheet '7 Rhw NMN whw RN 3 wNN yPatented May 23,1972 I 3,664,085

8 Sheets-Sheet 8 PACKAGING MACHINE BACKGROUND OF THE INVENTION Thisinvention relates to an apparatus and method for vacuum packaging of aproduct such as luncheon meat, cheese, frankfurters, or the like withina hermetically sealed, self-supporting container. The method andapparatus are particularly adapted to assemble the two element containeror package illustrated and described in Tigner U.S. Pat. No. 3,454,158.This package consists of a preformed, relatively fiat, rigid baseelement and a preformed inwardly concave rigid cover element. Asemployed herein the term rigid is intended to mean that the packageelement maintains'its own shape without internal or external supportsand thus is distinguishable from the types of packages wherein one orboth of the package elements is merely a thin pliable film. As describedherein the package elements or parts are adhesively joined together inthe manner described in the Tigner patent, although it will beappreciated that under certain conditions heat sealing equipment couldbe incorporated into or employed in conjunction with the disclosedapparatus. In the preferred embodiment no thermal forming or heatsealing equipment is needed, since the parts are preformed and theadhesive applied before the parts are handled by the machine.

The method and apparatus of the present invention feature a novel lid orbase down assembly technique which permits the product to be aligned onthe base and, thus, assures a uniformly neat package. Moreover, byaligning the product on the base prior to the positioning of the coveror shell, the danger of the product coming into contact with theperipheral edge of the shell is greatly minimized thereby assuring aclean surface for contact with the adhesive and providing a stronghermetic seal between the package parts.

SUMMARY OF THE INVENTION The apparatus vacuum packages a product such assliced luncheon meat in a two element package consisting of a preformedrigid base element and a preformed rigid cover element. In accordancewith one embodiment of the invention the apparatus includes a pluralityof platens and means, such as conveyor chains, for moving the platensthrough a plurality of operating stations. Each of the platens has apackage element holding means or nest thereon adapted to receive andhold the package elements in substantially aligned superposed relationon a predetermined portion of the platen. There are preferably two ormore such holding means on each platen. At the first operating stationof the apparatus there is means for placing a base element on eachpackage element holding means, and at the second station there is meansfor guiding the product into position on the base element.

After the product has been placed on the base element and before thecover element is positioned, it is preferred that there be means at athird station for aligning the product on the base element. This productalignment means is intended to assure that the product, particularly ifit is a stacked sliced product such as sliced meat or cheese, will bepackaged neatly and that the product will not contact the peripheral orsealing edge of the cover element before that edge engages the adhesivewhich preferably has been deposited in a peripheral mating groove on thebase element.

At the third operating station of the apparatus there is means forplacing a cover element over the product and base, and, finally, thereis a sealing station wherein a concave housing is moved into sealingengagement with the platen surrounding the package element holdingmeans. The cavity within the housing and the platen define apackage-accommodating vacuum chamber, and means is provided for applyinga vacuum to this chamber. An annular sealing member, which is carried bythe housing within the cavity, is normally held in an upwardly disposedor retracted position. Power means is provided for moving the sealingmember downwardly toward the platen while the housing is in sealingengagement with the platen, thereby forcing the peripheral or sealingportions of the package element into sealing engagement while the vacuumis maintained within the chamber.

Means is preferably provided for removing the sealed package from theplaten after the platen has been moved from the sealing station. Thismeans may be in the nature of a suction transfer device which transfersthe sealed package from one conveyor to another.

The preferred method of the invention includes the steps of placing arelatively flat rigid base element onto an imperforate platen, placing aproduct in proper alignment on the base element, loosely applying theconcave rigid cover element over the product with the peripheralportions of the cover element in close proximity with the peripheralportions of the base element, placing a concave housing over the coverand base elements with the portions thereof surrounding said elementsbeing in sealing engagement with the platen to form with the platen avacuum chamber surrounding the loosely assembled package elements,drawing a vacuum within the chamber, and while the vacuum is being held,forcing the peripheral portions of the cover element downwardly intosealing engagement with the peripheral portions of the base element andthen raising the pressure within the chamber to ambient.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view ofan apparatus constructed in accordance with this invention,schematically showing the various mechanisms and operating stations ofthe apparatus;

FIG. 2 is a top plan view of the apparatus illustrated in FIG. 1 showingthe platens on which the package elements are assembled and sealed;

FIG. 3 is a exploded view of the package element holding means, the twoelement package and the product, showing the manner in which these areassembled;

FIG. 4 is a sectional elevational view of a portion of a packageassembled by means of the apparatus and method of this invention;

FIG. 5 is a sectional elevational view taken substantially along line 55of FIG. 1 showing the construction of the platens, the platen guidemeans and the conveyor;

FIG. 6 is a top plan view of the platen illustrated in FIG. 5;

FIG. 7 is an end elevational view partially in section showing a portionof the mechanism for loading base elements onto the platens at the firststation;

FIG. 8 is a side elevational view of the base element loading mechanism,a portion of which has been broken away to show the manner in which themechanism operates to place a base element onto the package elementholding means of each platen;

FIG. 9 is a side elevational view of the product alignment mechanismshowing the position of the parts thereof as a platen is being movedinto position at this station;

FIG. 10 is an enlarged end elevational view of the product alignmentmechanism looking toward the front of the apparatus in the directionopposite the movement of the platens;

FIG. 10A is an enlarged sectional view taken substantially along linel0A-l0A of FIG. 10.

FIG. 1 l is a top plan of the product alignment mechanism;

FIG. 12 is an end elevational view of the product alignment mechanismlooking in the same direction as in FIG. 10 and showing the position ofthe parts as the mechanism engages the product to effect alignmentthereof;

FIG. 13 is a sectional view taken substantially along line 13-13 of FIG.1 and showing the vacuum sealing mechanism;

FIG. 14 is a sectional view taken substantially along line 14-14 of FIG.13 showing the sealing member carried by the housing within the cavityand the elements carried by the sealing member for engaging andcentering the cover element with respect to the base element as thesealing member is moved downwardly toward the platen;

FIG. 15 is a perspective view of the sealing member;

FIG. 16 is a top plan view of the package unloading mechanism whichremoves the sealed packages from the apparatus;

FIG. 17 is a side elevational view of the package unloading mechanism;and

FIG. 18 is an enlarged sectional view taken substantially along line18-18 of FIG. 17.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The method of this invention isparticularly adapted to be carried out on the apparatus illustrated inFIGS. 1 and 2 of the drawings. This apparatus operates to vacuum packagea product 12 in a two element package 14 of the type disclosed in theTigner US. Pat. No. 3,454,158 and illustrated in FIGS. 3 and 4 of thedrawings herein. The product 12 may, for example, be sliced luncheonmeat or sliced cheese, although it will be understood that the packageis adapted to hold a number of other products including such foodproducts as, for example, frankfurters and chili.

The package 14 is a two element package consisting of a preformed,relatively flat, rigid, i.e., self-supporting, base element 16 and apreformed, inwardly concave, rigid, i.e., selfsupporting, cover element18. The base element 16 is preferably formed of a polystyrene foamsheeting with a lamination of barrier film. The base element 16 has agenerally flat portion 20 adapted to receive and support the product 12and a marginal groove 22 adapted to securely receive the cover element18. An integral extension panel 23 may be provided as a convenient placefor printing the date code or the like. An aperture 23a in this panelprovides a convenient means for hanging the sealed package for consumerdisplay, and this aperture also facilitates alignment of the baseelement on the apparatus 10 as will be described herein.

The cover element 18 is preferably formed of a plastic web material byusual pressure-forming techniques, the plastic being of a thickness andof a nature to form a moistureproof and gastight barrier. The coverelement 18 may be transparent to allow viewing and inspection of theproduct 12, and this cover includes a top 24 and a peripheral side wall26 integral with the top and depending downwardly and outwardlytherefrom to engage the marginal groove 22 of the base element 16. It ispreferred that a soft tack adhesive be placed in the marginal groove 22of the base element 16 so that when the bottom edge of the side wall 26of the cover element comes into contact therewith, the two packageelements will be hermetically sealed.

An integral extension flange may be provided, this flange correspondingin size and shape to the extension panel 23 of the base element. Thisprovides a convenient location for a label and a means for grasping ofthe cover by the consumer when opening the adhesively sealed package. Anaperture 25a in this flange aligns with the aperture 23a in the baseelement when the elements are assembled.

In accordance with this invention the method for packaging the product12 in the two element package 14 comprises the steps of placing therelatively flat rigid base element 16 onto an imperforate surface suchas the platen 28 of the apparatus 10, placing the product onto the baseelement, aligning the product on the base element, loosely applying theconcave cover element 18 over the product 12 so that the peripheralportions are in close proximity with the corresponding peripheralportions of the base element 16, forming with the platen a vacuumchamber surrounding the loosely assembled package elements, drawing avacuum within the chamber, and while the vacuum condition exists forcingthe peripheral portions of the cover element downwardly into sealingengagement with the peripheral portions of the base element. Thereafter,the pressure within the chamber is raised to atmospheric whereby thepackage will be sealed by a combination of the reduced pressure withinthe package and the adhesive between the package elements.

As best illustrated in FIGS. 1 and 2 the apparatus 10 of this inventionhas a frame 30 on which is mounted an endless conveyor 32. The conveyor32 may, for example, include a pair of spaced, parallel chains 32a and32b, illustrated in cross section in FIG. 5. The chains are driven by asuitable electric motor 32c and commercially available index drive unit32a. The motor also drives a cam timer 33. Extending between the chains32a and 3211 are a plurality of platens 28. At the top portion of thechain run the platens 28 ride upon and are guided by means of horizontalrails 36 and 37 affixed to the frame 30. Each platen carries threerollers 38, two of which engage and roll along the rail 37 and the otherroller of which engages and rolls along the rail 36. The three rollercontact on the rails 36 and 37 provides a nonrocking movement of theplaten along the upper run of the conveyor. Each platen 28 may also beguided in its movement along a rectilinear path by means of a bottomroller 39 which rides within a longitudinal track 40 affixed to theframe 30.

Carried on the top surface of each of the platens 28 are twopackage-holding elements 42 and 44. These package-holding elements areidentically constructed, each having a base plate 46, the top surface ofwhich is covered with a resilient rubberlike cushion 48 having a raisedcentral portion 480 and a recessed peripheral portion 48b. The cushion48 is thus shaped to accommodate the bottom of the package base element16. The recessed peripheral portion of the cushion 48 is adapted toreceive the marginal groove 22 of the base element, and the centralportion may include recesses 48c in order to accommodate stacking oranti-jamming lugs molded on the bottom side of package base element 16.A longitudinally extending central groove 48d is also preferablyprovided in the central portion 48a to assure quick separation of thebase element 16 from the central portion of the holding element aftervacuum sealing.

In order to maintain the base element 16 in proper position on thecushioned package-holding element 42 or 44, as the case may be, aplurality of upstanding peripheral members or tabs 50 are provided.These tabs are high enough not only to position the base element 16 butalso the cover element 18. In the preferred embodiment these tabs aredisposed along three sides of the base plate at one end thereof. At theother end of the package-holding element is an upstanding taperedprotuberance or spike 52. The spike 52 is adapted to engage in the holes23a and 25a, respectively, of the base element extension 23 and coverflange 25.

The package-holding elements 42 and 44 are adapted to hold the packageelements in position as the assembly operations are carried out by theapparatus 10. The conveyor 32 indexes the platens 28 through a number ofoperating stations, the platen remaining in each station a sufficientlength of time for the assembly operation at that station to be carriedout. In the illustrated embodiment of the apparatus 10 a base elementloading mechanism 54 loads the package base elements 16 onto thepackage-holding elements 42 and 44 of the platens at the first operatingstation. At the second station a coding mechanism 56 stamps a suitablecode on the base element. At the third station a product guide 58 guidesthe product into position on the base elements, In the fourth station aproduct alignment mechanism 60 aligns the product on the base ele ments16. At the fifth station a cover element loading mechanism 62 places acover element over the aligned product in such a manner that the packageelements are loosely assembled. At the sixth station a sealing mechanismevacuates the package and seals it, and at the seventh and final stationan unloading mechanism 66 unloads the assembled package with the producttherein from the package-holding elements of the platens, and preferablyplaces this package on a take-off conveyor 68 or the like.

In the drawings the direction of platen movement is indicated by thearrows and is from left to right as viewed in FIGS. 1 and 2. Forpurposes of description the left-hand end of the apparatus 10 is calledthe forward or front end of the machine, and the right-hand end iscalled the rearward or discharge end of the machine. Directionsdescribed as upstream and downstream are given with respect to thedirection of platen movement.

The structure of the base element loading mechanism 54 is bestillustrated in FIGS. 7 and 8 of the drawings. The base element loadingmechanism 54 includes a support structure 70 connected to the frame 30of the apparatus. The support structure includes two upstanding sidemembers 70:: and 70b and a top cross member 700. Connected to andextending upwardly from the cross member 700 of the support structureare two hoppers 72 and 74 of substantially rectangular cross sectionadapted to accommodate a stack of package base elements 16 The hoppers72 and 74 are open along one side, preferably their downstream side,with the tops of the hoppers being tilted upstream or away from the openside. Thus, a stack of base elements 16 may be inserted easily into eachof the hoppers as shown in FIGS. 7 and 8, and there will be no tendencyfor them to fall through the open side.

Below the hopper 72 at the cross member 700 are mounted a pair ofgrippers 76 and 78, and a similar pair of grippers 80 and 82 are mountedbeneath the hopper 74. The grippers are merely plates having a smallinwardly disposed flange 83 along the bottom edge thereof. The grippers76 and 80 are fixedly connected to the top cross member 70c of thesupport structure 70. However, the grippers 78 and 82 are movable. Thegripper 78 is movable inwardly toward and away from gripper 76, thismovement being effected by means of an air cylinder 84. A second aircylinder 86 (see FIG. 1) is provided for moving the gripper 82 towardand away from the fixed gripper 80 beneath the hopper 74. Pivotallymounted between the upstanding members 700 and 70b of the supportstructure 70 is a bar 88 at the center of which is affixed an aircylinder 90. At the end of the operating shaft (piston arm) 90a of thecylinder 90 is affixed a crosshead 92 carrying a pair of resilientsuction cups 94 and 96. These suction cups 94 and 96 are operativelyconnected to a vacuum source 98 (see FIG. 1) by means of flexibleconduits 94a and 96a, respectively.

The bar 88 is rotated by means of a fluid operated rotary actuator 100,which may be an air cylinder, the normal linear reciprocal output motionof the piston of which is converted to rotary motion through a rack andpinion arrangement. Operation of the rotary actuator 100 will thusresult in the rotation of the bar 88 and of the apparatus carriedthereby including the crosshead 92 and the suction cups 94 and 96. Thecylinders 84, 86 and 90 and the rotary actuator 100 are operated from asource of fluid pressure such as an air compression unit 102,schematically illustrated in FIG. 1. The timing of the operation ofthese cylinders and the actuator may be controlled by means of thetiming mechanism 33, also schematically illustrated in FIG. 1.

The grippers 76 and 78 below the hopper 72 and the grippers 80 and 82below the hopper 74 are normally disposed inwardly toward each otherjust sufficiently to prevent the stack of base elements 16 storedtherein from falling through the bottom. When a platen 28 has moved intothe first station the timing mechanism 33 actuates the air pistoncylinders 84 and 86 to move the movable grippers apart so that the stackof base elements will move downwardly and rest on the resilient suctioncups 94 and 96 carried by the crosshead 92. At this time a vacuum orsuction is applied to the cups through the conduits 94a and 96a causingthe cups to attach by suction to the lowermost base element in thestack. At this point the air cylinders 84 and 86 are again actuated tomove the movable grippers 78 and 82 toward the fixed grippers 76 and 80,gripping the edges of the package base elements in the two hoppers 72and 74.

The air cylinder 90 then is actuated (reversed) to retract the operatingarm 90a, drawing the crosshead 92 and the suction cups 94 and 96downwardly with the lowermost base elements 16 in the two stacks 72 and74 attached thereto. Thus, the lowermost base elements will be strippedfrom the stack, and the rest of the base elements in the stack will beheld in position by means of the grippers. At this point the bar 88 isrotated by means of the rotary actuator 100 moving the two base elementsto a position above the package-holding elements 42 and 44 on the platenin the first station. This position is illustrated by broken lines inFIG. 8. The cylinder 90 is then actuated to extend the operating armoutwardly and position the base elements 16 on the package-holdingelements of the platens, and at this time the vacuum in the cups 94 and96 is released by suitable valving mechanisms (not shown). In fact, aslight positive pressure may be applied to the conduits 94a and 96a inorder to assure separation of the base elements from the suction cups.The cylinder is then reversed to retract the arm 90a and crosshead 92.The rotary actuator is reversed to return the bar 88 and the crosshead92 to its original position illustrated in FIGS. 7 and 8, and thecylinder 90 is operated to extend the crosshead and cups 94 and 96upwardly into position for attaching to the next base elements in thehoppers 72 and 74. The platen 28 with the two base elements 16 beingcarried thereon is then indexed to the next station.

At the next station there may be a coding mechanism 56, although this isoptional with the user of the machine. Frequently it is desirable tostamp on the package a code indicating perhaps the date or otheridentification of the packaging run. The illustrated coding mechanismshown in FIG. 1 includes two standard endless band stamping devices 104such as are commonly used in offices for stamping dates. The handle ofeach stamping device is operatively connected to the operating rod 105of an air cylinder 106, the air cylinder being mounted on a support 107attached to the apparatus frame 30. The cylinder 106 and stampingdevices 104 may be operated by means of the timing mechanism 33. Theplaten 28 with the stamped elements 16 carried thereon is then indexedto the next station.

The next station is preferably the product loading station where aproduct guide 58 is positioned for guiding the product onto the baseelement 16. If desired, an automatic mechanism may be utilized forplacing the stack of meat or other product which is being packaged ontothe base element 16 of the package. However, in the illustratedembodiment this is done manually as best illustrated in FIG. 2. Twoauxiliary conveyors 108 and 109 may be employed for this purpose, theseauxiliary conveyors being located on opposite sides of the apparatus 10.The platen 28 with the two base elements thereon is indexed to and comesto rest in the loading station in underlying alignment with a productguide 58. The product guide 58 includes two identically constructedsections 580 and 5812. Each guide section may be formed of sheet metalhaving three integral vertically extending sides including a pair ofspaced, parallel,longitudinally extending sides 110 and 112 and atransverse side 111 which extends between and interconnects the sides110 and 112. Each guide section is thus open along its top, bottom anddownstream sides. A web 113 connects the side 110 of each guide sectionto the apparatus frame 30. The spacing between the sides 110 and 112 ofeach product guide section is just sufficient to accommodate the productwhich in this case is a stacked meat product. The operator simplyinserts the meat stack into the guide section and onto the underlyingbase element 16. The two product guide sections 58a and 58b are shown intransverse alignment; however, if desired these may be positioned inlongitudinally staggered relation, in which case there would be twoconsecutive product loading stations, one for one side of the platen 28and the other station for the other side of the platen. Whetherstaggered or aligned the sections may be interconnected if desired,although in the illustrated embodiment they are separate.

The product alignment mechanism 60 located at the next operating stationof the platen is shown in detail in FIGS. 9 through 12. In theillustrated embodiment the product alignment mechanism 60 includes amechanism frame 116 comprising a rectangular support structure 118 andtwo pairs of depending posts 119 and 120 which are fixed to theapparatus frame 30. The rectangular support structure 118 includes apair of transverse members 122 and 124 which are interconnected by meansof longitudinal members 126 and 128, the longitudinal members beingsupported on the post pairs 119 and 120, respectively. Mounted atop thesupport structure 118 between the transverse members 122 and 124 is aplate 130 on which is mounted an air cylinder 132. The operating shaftor piston rod 134 of the cylinder 132 extends downwardly through theplate 130, and a subframe 136 is affixed to this shaft, so that thecylinder 132 may be operated in one direction to raise the subframe 136,and in the other direction to lower the subframe.

Attached to and depending from the subframe 136 are two guide boxes 138and 140 which support the guide two product alignment devices 142 and144 of the product alignment mechanism 60. Two alignment devices arerequired for the lilustrated embodiment of the invention in view of thefact that two packages are being'assembled on each platen 28simultaneously. The two product alignment devices 142 and 144 areidentically constructed. Each device includes a first pair of spaced,parallel, vertically disposed, relatively movable product-engagingplates 146 and 148 and a second pair of spaced, vertically disposed,relatively movable product-engaging plates 150 and 152 which areparallel to each other and are perpendicular to the first pair ofplates. Since the illustrated product 12 is a rectangular stack havingtwo pairs of parallel vertical sides, the product-engaging plates ineach pair of plates 146 and 148, and 150 and 152, are also parallel. Ifthe product 12 were round, the plates could be arcuate and perhaps onlyone pair of plates would be required for alignment. As a practicalmatter, however, the plates do not have to conform to the shape of theproduct. All that is necessary is that they conform to the size of theproduct, and this is a matter of simple adjustment as will be described.Thus the present arrangement of plates will handle both round andrectangular shaped products.

The plate 146 of the first pair of plates is connected to a horizontalbar 154 by means of the vertical arms 155, and the plate 148 isconnected to a horizontal bar 156 by the vertical arms 157. The bars 154and 156 are parallel to each other. In like manner, plate 150 of thesecond pair of product-engaging plates is connected to a bar 158 bymeans of vertical arms 160, and the product-engaging plate 152 isconnected to the bar 162 by means of the depending arms 163. Each of theproduct alignment devices 142 and 144 is operated by a pair of aircylinders 164 and 166. The air cylinder 164 is connected to the bar 156from which the product-engaging plate 148 depends, and the air cylinder166 is connected to the bar 158 from which the product-engaging plate150 depends.

The interconnection of the bars from which the pairs of product-engagingplates depend is best illustrated in FIG. A. The guide box 138 which isillustrated in FIG. 10A has side portions 138a, 138b, 1380 and 138d. Aspreviously stated the air cylinder 166 connected to the bar 158 has apiston rod 168 which extends through an aperture 158' in the bar. Thepiston rod also extends throughan aperture 138a in the side 138a of theguide box, and through an aperture 138C in the opposite wall 138: of theguide box. The end of the operating arm 168 is connected to the bar 162.A pair of guide rods 170 and 172 are also provided. The guide rod 170 isaffixed to the bar 162 and extends through and is disposed for slidingmovement within apertures in the side walls 1380 and 138a of the guidebox and an aperture in the bar 158. In like manner the guide rod 172affixed to the bar 158 extends through and is disposed for slidingmovement within apertures in the side walls 138a and 138a of the guidebox and an aperture in the bar 162.

The transverse parallel sides 13812 and 138d of the guide box 138 aresimilarly apertured for slidingly accommodating the piston rod 174 ofthe cylinder 164 and the guide rods 176 and 178. The air cylinder 164 isconnected to the rod 156, and the piston rod 174 of that cylinder isconnected to the rod 154. The guide rods 176 and 178 are respectivelyconnected to the rods 154 and 156.

Each of the operating rods and guide rods carries a stop which may be inthe form of a turned shoulder and which is larger in diameter than theapertures in the guide box side walls. Thus the stop 180 is carried onthe piston rod 168, the stop 18] is carried on the guide rod 170, andthe stop 182 is carried on the guide rod 172. In like manner the stop184 is carried on the piston rod 174 of the air cylinder 164, the stop185 is carried on the guide rod 176, and the stop 186 is carried on theguide rod 178. The location of the stops on the rods governs theposition of the movable members in their open and closed positions. Thestops and 184 on the piston rods of the air cylinders 166 and 164 governthe position of the bars 158 and 162 and the bars 156 and 154 in theirclosed positions illustrated in FIG. 12, where the product-engagingplates are in engagement with the product 12 on the package base plate16. In similar manner the stops 181 and 182 on the guide rods 170 and172 and the stops and 186 on the guide rods 176 and 178 will govern theposition of the bars and the productengaging plates in the open positionillustrated in FIG. 10. While these stops can be made to be adjustableit is preferred that any adjustment be made by means of spacer elements188 between the product-engaging plates and their vertical arms. Thelocation of the stops is preferably such that when the product-engagingplates are in their open position, they will align with the outerextremity of the marginal groove 22 in the package base element 16, andwhen these plates are in their closed position they will just slightlycompress the product 12.

As previously stated the subframe 136 which carries the two alignmentdevices 152 and 144 is moved upwardly and downwardly on the piston rod134 of the cylinder 132. Affixed to and extending vertically upward fromthe movable subframe 136 in spaced parallel relationship with the pistonrod 134 of the cylinder 132 is a rod 190. The rod 190 extends through anaperture in a plate 192 affixed to the mechanism frame 116 above thesubframe 136. The sliding movement of the vertical rod 190 in theaperture of the plate 192 thus serves to guide the vertical movement ofthe subframe.

Means is preferably provided on the alignment mechanism 60 for pressingthe base element 16 flat on the package-hold ing elements 42 and 44while the product is being centered or aligned. Afiixed to the subframe136 are two extension plates 194 and 196. Affixed to and depending fromthe plate 194 is a bar 198 (see FIG. 9), and at the lower end of thisbar is a coil spring 200. The bar 198 and coil spring 200 are verticallyaligned with the spike 52 on the package-holding element 44. In likemanner a bar 202 is affixed to and depends downwardly from the extensionplate 196 and carries a coil spring 204 at its lower end. The bar 202and coil spring are vertically aligned with the spike 52 on thepackage-holding element 42. The coil springs 200 and 204 are adapted tobe moved over the spikes 52 and to resiliently press the flanges 23 ofthe base elements 16 flat on the package-holding elements 42 and 44 whenthe subframe is moved dovmwardly to its lowered position as illustratedin FIG. 12. This insures proper placement of the two package baseelements 16 while the two products are being centered thereon by themechanism 60.

The dimensions of the parts of the alignment mechanism 60 and length ofthe stroke of the piston rod 134 are such that when the subframe is inits raised position (as in FIG. 10), the product-engaging plates will beabove the level of the product 12 as the package base element 16 and theproduct are moved into the alignment station on the platen 28, and whenthe subframe is in its lowered position (as in FIG. 12) the plates willbe spaced just above the package base element 16 so that all slices orportions of the product 12 will be engaged during alignment.

In operation, when the platen with the product such as a sliced meat orcheese on the package base element 16 is moved into position beneath theproduct alignment mechanism 60, this mechanism is actuated by the timer33 which operates an air control unit 205 (such as a solenoid valve)operatively connected to the pressure tank 98 (see FIG. 1). The aircontrol unit first actuates the cylinder 132 to move the piston rod 134and the subframe 136 downwardly. As the product-engaging plates 146,148, 150 and 152 of each of the product alignment devices 142 and 144carried on the subframe 136 approach the platen 28, the springs 200 and204 will press the flanges of the base elements 16 over the spikes 52,flattening and assuring proper alignment of the base elements on thepackage-holding elements 42 and 44. When the subframe reaches theposition illustrated in FIG. 12, the cylinders 164 and 166 of each ofthe product alignment devices 142 and 144 are actuated (also by means ofthe timer 33 and control unit 205), causing the product-engaging platesto move inwardly toward each other to engage the product on the packagebase element 16.

It is preferred that the cylinders 164 and 166 be cycled,

twice, that is, actuated in each direction twice, so that theproduct-engaging plates will engage the product twice, because it hasbeen found that the best alignment of the product is accomplished inthis manner. This is particularly true of a sliced meat or cheeseproduct where it may not only be necessary to align a product on thebase element 16, but it may also be necessary to make sure that all ofthe slices are aligned with one another. After the product-engagingplates have moved inwardly twice, the cylinder 132 is actuated in theopposite direction to raise the subframe and the product alignmentdevices 142 and 144. The platen 28 is then indexed by the conveyormechanism 32 to the next station which is the cover loading station.

The cover element loading mechanism 62, best shown in FIG. 1, ispreferably constructed exactly like the base element loading mechanism54 previously described and illustrated in FIGS. 7 and 8 of thedrawings. Since, however, the configuration of the cover element 18 isslightly different from the base element, the stroke of the cylinder 206will be slightly longer, and the hoppers and gripping elements may beslightly different to accommodate the difference in shape of the coverelements. The operation of the cover element loading mechanism 62 is bythe timer 33; however, in addition to the timer it is preferred thatphotoelectric sensing units 208 be employed to detect the presence ofproduct on the base elements 16 carried by the package-holding elements42 and 44 of the platen. Each sensing unit is of standard constructionemploying a light source and a photocell. If desired, two photoelectricunits 208 may be employed for this purpose so that the cover elementloading mechanism will only deposit one cover element 18 if there isonly one product stack on the platen. Thus the suction lines to thesuction cups could be individually controlled by a respective one of thephotoelectric units. It also may be desired to employ vacuum switches210 in the line to the suction cups to sense whether a cover is actuallyin contact with the vacuum cup. If no cover is transported by the coverelement loading mechanism 62, then the vacuum switch would shut off themachine at the end of the cycle, and the platen would not index. In suchcase a suitable warning such as a bell, buzzer or light could becontrolled by the vacuum switch 210. The same type of vacuum switchcontrol may be employed with the base element loading mechanism 54 tosignal when either or both of the vacuum cups 94 and 96 are not incontact with a base element 18 when the suction is applied through thelines 940 and 96a.

The cover element loading mechanism 62 is adapted to place a coverelement 18 over the stacked and aligned product 12 on the base element16 with the lower depending edges of the cover element in closeproximity with the corresponding peripheral edges of the base element 16as previously described. The cover element loading mechanism 62 looselyapplies the cover so that there is no hermetic seal between the base andcover elements at this stage of the assembly operation.

Following delivery of the cover element by the cover element loadingmechanism 62, the conveyor 32 is indexed to the next station which isthe sealing station, and in passing from the cover element loadingmechanism 62 to the sealing mechanism 64 at the sealing station, theloosely assembled package elements will pass in front of a second set ofphotoelectric detection units 209. Again, if desired, there may be morethan one such unit 209 in order to detect the presence of the package oneach of the package-holding elements 42 and 44 of the platen.

The sealing mechanism 64 is illustrated schematically in FIG. 1 and inmore detail in FIG. 13 with parts thereof being shown in FIGS. 14 and15. This mechanism includes a pair of vertical posts 211 and 212 fixedin sockets 214 and 216, respectively, the sockets 214 and 216 beingwelded or otherwise firmly anchored to the apparatus frame 30. Mountedfor sliding vertical movement on the posts 211 and 212 is a bell housing218. In the illustrated embodiment the bell housing 218 is formed in twoparts, a top part 218a and a lower part 21812, the two parts beingjoined together by means of suitable bolts or the like not shown in thedrawings. The lower portion 2l8b of the housing is a rectangular annulushaving slightly smaller dimensions than the platen 28. Thus the housing218 is concave and adapted to fit over the central portion of the platen28 where the package-holding elements 42 and 44 are mounted. The loweredge of the lower portion 218b of the bell housing has a resilient seal220 which when the bell housing is lowered onto the platen 28, willperipherally engage the platen and effect an airtight seal between theplaten and the housing. When lowered into the position illustrated inFIG. 13 the bell housing 218 and the platen 28 form a vacuum chamber 222surrounding the package-holding elements 42 and 44, and the packageelements 16 and 18, and product 12 which has been placed therebetween.

The bell housing 218 is rigidly connected to a carriage plate 224 bymeans of suitable structure such as the vertical braces 226. The plate224, in turn, is connected to the piston or operating rod 228 of a fluidcylinder 230 illustrated in FIG. 1. The fluid cylinder 230, in turn, isaffixed to a stationary plate 231 which is attached to the posts 211 and212 near the tops thereof. Mounted atop the bell housing 218 between thebell housing and the carriage plate 224 are two fluid cylinders 232 and234. The piston rods 232a and 234a of these cylinders extend into theinterior of the housing upper portion 218a through the cylinder endportions 237 and 236, respectively. The seal between the respectivecylinder end portions 236 and 237 and the housing upper portion 218a issuch that there is no passage of air therebetween even under conditionsof relatively high vacuum within the concavity of the housing 218.

Within the concavity of the housing 218 are two sealing devices 238 and239. The sealing device 238 is disposed to the left as viewed in FIG. 13(looking upstream of the conveyor), this device being connected to thepiston rod 234a of the cylinder 234. The sealing device 239 is disposedto the right in FIG. 13 and is connected to and operated by the pistonrod 232a of the cylinder 232. The sealing device 238 includes asubstantially rectangular ring holder 240 having a top portion 240a, adepending skirt portion 240b and a central concavity 240C. The ringholder 240 is operatively connected to the piston rod 234a of the fluidcylinder 234 by means of an attaching rod 242 having a head portion 244and a shank portion 246. The rod shank portion 246 extends upwardlythrough the ring holder top 240a, a two-piece spherical selfaligningwasher 248, and a tightening nut 249. The upper end of the rod 242extends into and is locked in a connector 250 by means of a pin 252, theconnector, in turn, being afiixed to the output shaft 234a of thehydraulic cylinder 234 by means of a pin 254.

Afi'rxed to the skirt portion 240!) of the ring holder 240 and extendingdownwardly therefrom is a pressure ring 256. Attached to the inside ofthe pressure ring 256 are four cover element centering plates 257, 258,259, and 260 shown in HG. 14 of the drawings. The pressure ring 256 isillustrated in FIG. 15 of the drawings.

The pressure ring holder 240 carries a roller 262 disposed within theguideway 264 of the I-shaped guide member 266 as shown in FIG. 13.Disposed within the central concavity 2406 of the ring holder 240 is aknockout member 268 which is affixed to the upper portion 218a of thebell housing by suitable fasteners 270 and spacers 272 which extenddownwardly from the upper portion of the bell housing 218a into theconcavity defined by the rectangular annular lower portion 218b of thebell housing. The knockout 268 which is thus fixed to the housing 218has a top recess 268a for accommodating the head portion 244 of the ringholder attaching rod 242 which is attached to and reciprocates with thepiston rod 234a of the cylinder 234.

On the right-hand side of the bell housing cavity 222 (as viewed in FIG.13), the sealing device 239 is connected to and carried by the pistonrod 232a of the cylinder 232. The corresponding parts have been givenprime numbers corresponding to the parts of the sealing device 238 justdescribed. Thus, for the sealing device 238 the ring holder 240 isconnected to the output shaft 232a by means of an attaching rod 242having a head portion 244 and a shank portion 246 which extends throughthe ring holder top portion 240a, through a two-piece self-aligningwasher 248', a tightening nut 249 and into a connector 250'. A pin 252'locks the upper end of the rod 242' within the connector 250', and a pin254 locks the connector 250 to the piston rod 232a of the cylinder 232.The ring holder 240 has a depending skirt portion 240b which carries apressure ring 256 and a set of centering plates (only plates 257 and259' being shown in FIG. 13). A roller 262 attached to the ring holder240' is disposed within the vertical guideway 264 of the I-shaped guidemember 266.

In the upper portion 218a of the housing is a manifold 274 to which aconduit 276 is connected The conduit 276, in turn, is connected to avalve 278 controlled by the timer 33 (see FIG. 1). In one position ofactuation the valve 278 connects the conduit to the vacuum tank 102, andin the other position of actuation the valve connects the conduit to thepressure tank 98. If desired, two separate valves may be employed, avacuum valve for controlling air evacuation from the chamber and an airvent valve for controlling restoration of pressure within the chamber.

From the foregoing it will be apparent that the housing 218 with thesealing devices 238 and 239 carried therewithin is raised and lowered byactuation of the fluid cylinder 230 which raises and lowers the carriageplate 224 rigidly connected to the housing. The sealing devices 238 and239 within the housing cavity are operated by means of the cylinders 234and 232, respectively.

It is preferred that the photoelectric detection units 209, located justupstream from the sealing mechanism 64, be utilized in conjunction withthe timer 33 to control the operation of the cylinders 232 and 234 ofthe sealing mechanism.

When the housing 218 is first lowered into sealing engagement with theplaten 28, both sealing devices 238 and 239 will be in their vacuum orraised positions. The housing is lowered just sufficiently to obtain aface seal between the resilient peripheral seal 220 and the platen 28.When the vacuum is drawn, the platen 28 will actually be raisedslightly, increasing the seal at the periphery of the housing andremoving the loading on rollers 38. If the unit 209 has detected apackage on only one of the package element holding means 42 or 44, onlythe particular sealing device 238 or 239 as the case may be will belowered to effect sealing of the package elements.

In the illustrated embodiment there are package elements on the holdingmeans 44, but there is not package on the holding means 42.Consequently, the sealing unit 239 has remained in its raised or vacuumposition while the sealing unit 238 has been lowered to its sealingposition to effect sealing of the package elements.

As was previously described the package base element 16 has a marginalgroove 22, and it is preferred that there be a deposit ofpressure-sensitive adhesive in this groove. It is the function of thepressure ring 256 to force the side wall of the I package cover element18 downwardly into engagement with the inside of the package which isbeing formed. Thus, the sealing units 238 and 239 are in the raised orvacuum position when the vacuum is first drawn. After the vacuum hasbeen drawn, if the detection means 209 has detected the presence of apackage on both of the package element holding means 42 and 44, thenboth of the sealing devices will be actuated to move the pressure rings256 and 256 downwardly and force the bottom of the side wall 26 of eachof the two cover elements 18 into the marginal groove 22 of theirrespective base elements 16, thereby effecting a hermetic seal undervacuum conditions.

As the pressure ring 256 is moved downwardly the centering plates257-260, which will just accommodate the cover element 18, assure thatthe cover element is precisely aligned with the pressure ring 256 andwith the package element holding means 42 and 44. The centering platesare slightly tapered at their leading edge, and should the cover beoff-center slightly, the leading edge will engage the cover element 18and cam it into a precisely centered position, thereby assuring thealignment of the side wall 26 of the cover element with the marginalgroove 22 of the base element and assuring proper sealing of the twoelements when the pressure ring is in its lowered position. Precisealignment between the package base element 16 and the package coverelement 18 is accomplished by a combination of the holding means 42 and44 (which position the base element 16) and the centering plates 257-260(which align the cover element 18).

As has been stated, the pressure ring 256 is brought downwardly as avacuum condition is maintained within the chamber 222. Once the packagehas been sealed the sealing devices 238 and 239 are returned to theirraised position, and the vacuum is released within the chamber 222 tobring the pressure within the chamber at least to ambient. This vacuumrelease may be accomplished by venting the interior of the chamber tothe atmosphere, but in order to speed the operation of the machine it ispreferred that this be pressure vented by connecting the conduit 276 tothe air pressure tank 98 through the valve 278 or a separate air ventvalve. The venting of the chamber to restore ambient pressure may bedone immediately after sealing the package elements without waiting forthe sealing devices to be raised.

If desired, the system may employ a gas flush by providing for theinjection of, for example, an inert gas into the chamber 222 after thevacuum has been drawn and before sealing the package elements. Thus, ineffect, the chamber and the package are flushed with the inert gas. Thismay be desirable for some products including certain food products, andfor greatest efficiency a separate gas inlet could be provided in thehousing 218.

After the pressure ring has been moved downwardly to effect sealing ofthe package elements as has been described there may be a tendency inview of the rather tight fit between the centering plates 257-260 andthe cover element 18 for the package to retract with the sealing device238 and be lifted off of the package element holding means 44. However,this is prevented by the knockout device 268 which remains stationaryand prevents the package from moving upwardly into the cavity when thepressure ring and sealing plates are raised to their initial retractedposition. The knockout 268, in effect, strips the package from thepressure ring and centering plates, and the package thus remains on thepackage element holding means 44.

When the chamber 222 has been brought at least to ambient and preferablyslightly pressurized the housing 218 may be raised by actuation of thecylinder 230. The conveyor with the sealed package or packages thereonis then moved to the final operating station which is the unloadingstation.

The unloading mechanism 66 is best illustrated in FIGS. 16, 17 and 18.This mechanism includes a horizontal shaft 280 journaled in two supports282 and 283 having bases 282a and 283a which are adjustably connected tothe frame 30 of the apparatus by means of suitable threaded connectorsor bolts 284. One end of the horizontal shaft 280 is connected to afluid operated rotary actuator 286.

Adjacent the rotary actuator 286 the horizontal shaft 280 carries afirst or inner collar 288 fixed to the shaft by means of a set screw 290(see FIG. 18). The collar carries a pin 202. Surrounding the innercollar 288 is a second or outer collar 294 having a slot 295 therein.The fit between the inner collar 288 and the outer collar 294 is suchthat free rotation is permitted between these with the pin 292 carriedby the inner collar 288 disposed within the slot 295 of the outer collar294. This, in effect, is a lost motion connection between these twocollars. Affixed to the outer collar 294 is an arm 296 which extendsupwardly between two resilient abutments 298 and 299 affixed to thesupport 283. From this it is apparent that the rotation of the shaft 280is limited by the length of the slot 295 in the outer collar 294. Itwill be noted that the slot 295 extends approximately 180 so that theshaft 280 will be permitted to rotate approximately 180. The resilientabutments 298 and 299 serve as cushions to absorb the shock when theshaft 280 is stopped at the end of the 180 swing.

Mounted on the horizontal shaft 280 are two telescopingly adjustablearms 300 and 302. The end 300a of the arm 300 is locked in itsadjustment position by means of a lock nut 300b, and the end 302a of thearm 302 is locked in its position of telescoping adjustment by means ofa lock nut 302b. Journaled in the ends 300a and 3020 of the arms 300 and302 is a bar 304 which carries a pair of suction cups 306 and 308. Thesuction cups are connected by means of suction lines 306a and 308a tothe vacuum tank 102 illustrated in FIG. 1. Keyed to the end of the bar304 is a pulley 310, and a similar pulley 312 of the same diameter isaffixed to the support 282 as illustrated in FIGS. 16 and 17. Extendingaround the pulleys 310 and 312 is a wire 314. As the bar 304 is swung inthe counterclockwise direction from the dotted line position to thesolid line position, as illustrated in FIG. 17, the pulley 312 willremain stationary while the pulley 310 and the bar 304 will be rotatedat the same rate in the clockwise direction. Thus the bar 304 willmaintain its orientation with respect to the horizontal, and the suctioncups 306 and 308 will remain vertically disposed. This arrangementassures that the packages 14 will remain horizontally disposed as theyare lifted from the platen 28 and swung onto the auxiliary or take-offconveyor 68. The operation of the rotary actuator 286 and of the suctioncups 306 and 308 is preferably controlled by means of suitable valvessuch as the valve mechanism 278 which in turn is controlled by the timer33. v

In operation, when the platen is moved to its final station asillustrated in dotted lines in FIG. 17, the suction cups 306 and 308 aremoved downwardly to engage the cover tops 24 of the two packages 14which have just been assembled and sealed. A suction is then appliedthrough the lines 306a and 308a (see FIG. 6), and the fluid operatedrotary actuator 286 is actuated for counterclockwise rotation as viewedin FIG. 17 so that the arm 304 moves in the direction of the arrows inthat figure. The arm is swung from the dotted line position to the solidline position as shown in FIG. 17, the package and the suction cupsmaintaining the same orientation throughout this swinging movement aspreviously described. When the arm 296 engages the right-hand adjustableabutment 298 the package 14 will be just above the take-off conveyor 68as illustrated in FIG. 17. At this point the suction is released eitherby valving the lines 306a and 308a to the atmosphere or connecting themto the pressure tank 98 through a valve such as valve 278, therebyreleasing the package onto the take-ofi conveyor 68. The apparatus isthus adapted to package a product quickly, easily and efficiently in apreformed two element package.

It is to be understood that the present disclosure has been made only byway of example and that many modifications and changes in variousdetails may be readily apparent to those skilled in the art. Forexample, the operation of the various cooperating mechanisms ispreferably accomplished by air cylinders as has been described. Itwould, however, be entirely within the scope of the invention if thepower were supplied hydraulically or in some instances even electricallyby means of solenoids. Additional changes in the structural details andarrangement of parts may be resorted to without departing from theinvention.

What is claimed is:

1. An apparatus for vacuum packaging of a product in a two elementpackage consisting of a preformed rigid base element and a preformedrigid cover element, said apparatus comprising at least one platen,means on said platen for holding the package elements in substantiallyaligned superposed relation on a predetermined portion of said platen,said holding means including a plurality of upstanding members spaced toengage peripheral portions of the package elements to restrict thelateral movement of the package elements with respect to said platen, aconcave housing, means for moving said housing into sealing engagementwith said platen surrounding said holding means, whereby said housingconcavity and said platen define a package-accommodating vacuum chamber,means for applying a vacuum to said vacuum chamber, an annular sealingmember carried by said housing within said concavity, said sealingmember being normally held in an upwardly disposed retracted position,and power means for moving said sealing member downwardly toward saidplaten while said housing is in sealing engagement with said platen,whereby the peripheral portions of said package elements may be forcedinto sealing engagement while a vacuum is being applied to said chamber.

2. The apparatus of claim 1 wherein said holding means further includesa protuberance positioned to extend through a correspondingly positionedaperture in at least one of the package elements.

3. The apparatus of claim 1 wherein said holding means further includesa plate affixed to said platen, and a resilient cushion on said plate.

4. The apparatus of claim 3 wherein said cushion has a raised centralportion and recessed peripheral portions for accommodating theperipheral portions of said package elements when they are forceddownwardly by said sealing member.

5. The apparatus of claim 1 wherein there are a plurality of platens,and means is provided for moving said platens sequentially into andthrough a plurality of operating stations including a sealing station inwhich each platen is positioned for sealing engagement with saidhousing.

6. The apparatus of claim 1 and further including means for supplyinggas to the vacuum chamber at greater than atmospheric pressure after theperipheral portion of the package elements have been forced into sealingengagement by said sealing member.

7. The apparatus of claim 1 wherein said sealing member carries aplurality of tapered inwardly disposed elements for engaging andcentering the cover element with respect to the base element as saidsealing member is moved downwardly toward said platen.

8. The apparatus of claim 1 and further including means disposedinteriorly of said sealing member and connected to said housing fordislodging the package elements from said sealing member when saidsealing member is returned to its retracted position.

9. The apparatus of claim 5 wherein horizontal guide means is providedfor maintaining said platens in a substantially horizontal orientationas they are moved into and through said operating stations, and verticalguide means is provided for guiding said platens along a substantiallystraight path.

10. The apparatus of claim 1 wherein on each platen there are aplurality of means for holding the package elements, whereby a pluralityof packages may be assembled and sealed on each platen simultaneously.

11. An apparatus for vacuum packaging of a product in a two elementpackage consisting of a preformed relatively flat rigid base element anda preformed inwardly concave rigid cover element, one of said packageelements carrying an adhesive whereby when the package elements arepressed together an hermetic seal will be formed therebetween; saidapparatus comprising a plurality of platens, means adapted to move saidplatens sequentially along a predetermined path through a plurality ofoperating stations, each of said platens having package element holdingmeans thereon adapted to receive and hold the package elements insubstantially aligned superposed relation on a predetermined portion ofthe platen, first package element placement means for placing a baseelement on said package element holding means at a first station, meansfor guiding the product into position on the base element at a secondstation, second package element placement means for placing a coverelement over the product and base at a third station, a concave housing,means for moving said housing into sealing engagement with said platensurrounding said package element holding means at a fourth station,whereby said housing cavity and said platen define apackageaccommodating vacuum chamber, means for applying a vacuum to saidvacuum chamber, an annular sealing member carried by said housing withinsaid concavity, said sealing member being normally held in an upwardlydisposed retracted position, and power means for moving said sealingmember downwardly toward said platen while said housing is in sealingengagement with said platen, whereby the peripheral portions of saidpackage elements may be forced into sealing engagement while a vacuum isbeing applied to said chamber.

12. The apparatus of claim 1 l and further including product alignmentmeans intermediate said product guiding means and said cover placingmeans for aligning the product on the base element.

13. The apparatus of claim 11 wherein at least one of said packageelement placement means includes means above said conveyor at theassociated station for holding a stack of package elements, an armmounted for movement relative to said frame and carrying package elementattachment means for engaging and releasably attaching to the lowermostpackage element in the stack, means for moving said arm first to effectremoval of the attached package element from the stack and then toeffect movement of the package element onto said package element holdingmeans.

14. The apparatus of claim 13 wherein said arm is pivotally mounted onsaid frame and is movable first radially inwardly to effect removal ofthe attached package element, then is pivotally moved to a positionabove said holding means and then is moved radially outward to place thepackage element in said holding means.

15. The apparatus of claim 13 wherein said means carried by said arm forengaging and releasably attaching to the lowermost package element inthe stack is a resilient cup, and means is provided for drawing a vacuumwithin said cup when said cup is in engagement with the lowermostpackage element in the stack and for releasing the vacuum when thatpackage element has been moved onto said package element holding means.

16. The apparatus of claim 12 wherein said product alignment meansincludes a subframe, at least two product engaging members mounted onsaid subframe for limited movement toward and away from each other, andmeans for moving said subframe from a raised position above said packageelement holding means to a lowered position within said package elementholding means whereby when said members are moved toward each other theywill engage and align the product on the base element within saidholding means.

17. The apparatus of claim 12 wherein there are two package elementholding means on each platen, and said product alignment means includesa subframe, at least two sets of product alignment plates carried bysaid subframe, each set comprising two pairs of plates, the plates ineach pair being substantially parallel and relatively movable withrespect to one another, the pairs of plates in each set being disposedsubstantially perpendicular with respect to one another, means formoving said subframe from a raised position above said package elementholding means to a lowered position, and means for moving the plates ineach set toward each other to substantially simultaneously engage andalign the products on the base elements within said two package elementholding means.

18. The apparatus of claim 17 wherein said product alignment meansincludes two pairs of product engaging members, said pairs being mountedon said subframe for transverse movement with respect to each other,whereby the product may be aligned on four sides.

19. The apparatus of claim 11 and further including means for removingthe sealed package from said platen after said platen has moved from thesealing station.

20. The apparatus of claim 19 wherein said means for removing the sealedpackage from said platen includes at least one suction cup, means formoving said suction cup between two locations, and means for applying asuction to said suction cup in one location and releasing it in theother location, whereby said suction cup may attach to the package insaid one location and the package may be transported to and released insaid other location.

21. The apparatus of claim 19 wherein said means for removing the sealedpackage from said platen includes a support, an arm mounted on saidsupport for pivotalmovement about a horizontal axis, package attachmentmeans mounted on said arm for rotational movement about a horizontalaxis, and means for rotating said package attachment means relative tosaid arm at substantially the same angular rate and in the oppositedirection as the pivotal movement of said arm with respect to saidsupport, whereby said package attachment means will maintainsubstantially the same orientation with respect to the horizontalthroughout the pivotal movement of said arm.

22. The apparatus of claim 20 wherein said means for rotating saidpackage attachment means relative to said arm includes a first pulleyafiixed to said support, a second pulley affixed to said packageattachment means, and an endless band encircling said pulleys.

23. An apparatus for vacuum packaging of a product in a packageconsisting of two rigid package elements, said apparatus comprising aplurality of platens, means for moving said platens sequentially along apredetermined path through a plurality of operating stations, each ofsaid platens having package element holding means thereon adapted toreceive and hold the package elements in substantially alignedsuperposed relation on a predetermined portion of the platen, means forholding a supply stack of each of said preformed package elements andfor sequentially transferring said elements from the supply stacks tosaid platens at predetermined operating stations, a concave housing,means for moving said housing into sealing engagement with said platensurrounding said package element holding means after said packageelements have been positioned thereon, whereby said housing cavity andsaid platen define a package-accommodating vacuum chamber, means forapplying a vacuum to said vacuum chamber, an annular sealing membercarried by said housing within said concavity said sealing member beingnormally held in an upwardly disposed retracted position, and powermeans for moving said sealing member downwardly toward said platen whilesaid housing is in sealing engagement with said platen, whereby theperipheral portions of said package elements may be forced into sealingengagement while a vacuum is being applied to said chamber.

24. An apparatus for vacuum packaging of a product in a two elementpackage consisting of a preformed relatively flat rigid base element anda preformed inwardly concave rigid cover element; said apparatuscomprising a plurality of platens, means adapted to move said platenssequentially along a predetermined path through a plurality of operatingstations, each of said platens having package element holding meansthereon adapted to receive and hold the package elements insubstantially aligned superposed relation on a predetermined portion ofthe platen, first package element placement means for placing one ofsaid elements on said package element holding means at a first station,means for guiding the product into position with respect to said oneelement at a second station, second package element placement means forplacing the other of said elements over the product and said one elementat a third station, a concave housing, means for moving said housinginto sealing engagement with said platen surrounding said packageelement holding means at a fourth station, whereby said housing cavityand said platen define a package-accommodating vacuum chamber, means forapplying a vacuum to said vacuum chamber, an annular sealing membercarried by said housing within said concavity, said sealing member beingnormally held in an upwardly disposed retracted position, and powermeans for moving said sealing member downwardly toward said platen whilesaid housing is in sealing engagement with said platen, whereby theperipheral portions of said package elements may be forced into sealingengagement while a vacuum is being applied to said chamber.

25. An apparatus for vacuum packaging of the product in a two elementpackage consisting of a preformed rigid base element and a preformedrigid cover element, said apparatus comprising at least one platen, aplurality of means on said platen for holding the package elements insubstantially aligned superposed relation on a predetermined portion ofsaid platen, whereby a plurality of packages may be assembled and sealedon each platen simultaneously, a concave housing, means for moving saidhousing into sealing engagement with said platen surrounding saidholding means, whereby said housing concavity and said platen define apackage-accommodating vacuum chamber, means for applying a vacuum tosaid vacuum chamber, an annular sealing member carried by said housingwithin said concavity, said sealing member being normally held in anupwardly disposed retracted position, and power means for moving saidsealing member downwardly toward said platen while said housing is insealing engagement with said platen, whereby the peripheral portions ofsaid package elements may be forced into sealing engagement while avacuum is being applied to said chamber.

1. An apparatus for vacuum packaging of a product in a two elementpackage consisting of a preformed rigid base element and a preformedrigid cover element, said apparatus comprising at least one platen,means on said platen for holding the package elements in substantiallyaligned superposed relation on a predetermined portion of said platen,said holding means including a plurality of upstanding members spaced toengage peripheral portions of the package elements to restrict thelateral movement of the package elements with respect to said platen, aconcave housing, means for moving said housing into sealing engagementwith said platen surrounding said holding means, whereby said housingconcavity and said platen define a package-accommodating vacuum chamber,means for applying a vacuum to said vacuum chamber, an annular sealingmember carried by said housing within said concavity, said sealingmember being normally held in an upwardly disposed retracted position,and power means for moving said sealing member downwardly toward saidplaten while said housing is in sealing engagement with said platen,whereby the peripheral portions of said package elements may be forcedinto sealing engagement while a vacuum is being applied to said chamber.2. The apparatus of claim 1 wherein said holding means further includesa protuberance positioned to extend through a correspondingly positionedaperture in at least one of the package elements.
 3. The apparatus ofclaim 1 wherein said holding means further includes a plate affixed tosaid platen, and a resilient cushion on said plate.
 4. The apparatus ofclaim 3 wherein said cushion has a raised central portion and recessedperipheral portions for accommodating the peripheral portions of saidpackage elements when they are forced downwardly by said sealing member.5. The apparatus of claim 1 wherein there are a plurality of platens,and means is provided for moving said platens sequentially into andthrough a plurality of operating stations including a sealing station inwhich each platen is positioned for sealing engagement with saidhousing.
 6. The apparatus of claim 1 and further including means forsupplying gas to the vacuum chamber at greater than atmospheric pressureafter the peripheral portion of the package elements have been forcedinto sealing engagement by said sealing member.
 7. The apparatus ofclaim 1 wherein said sealing member carries a plurality of taperedinwardly disposed elements for engaging and centering the cover elementwith respect to the base element as said sealing member is moveddownwardly toward said platen.
 8. The apparatus of claim 1 and furtherincluding means disposed interiorly of said sealing membEr and connectedto said housing for dislodging the package elements from said sealingmember when said sealing member is returned to its retracted position.9. The apparatus of claim 5 wherein horizontal guide means is providedfor maintaining said platens in a substantially horizontal orientationas they are moved into and through said operating stations, and verticalguide means is provided for guiding said platens along a substantiallystraight path.
 10. The apparatus of claim 1 wherein on each platen thereare a plurality of means for holding the package elements, whereby aplurality of packages may be assembled and sealed on each platensimultaneously.
 11. An apparatus for vacuum packaging of a product in atwo element package consisting of a preformed relatively flat rigid baseelement and a preformed inwardly concave rigid cover element, one ofsaid package elements carrying an adhesive whereby when the packageelements are pressed together an hermetic seal will be formedtherebetween; said apparatus comprising a plurality of platens, meansadapted to move said platens sequentially along a predetermined paththrough a plurality of operating stations, each of said platens havingpackage element holding means thereon adapted to receive and hold thepackage elements in substantially aligned superposed relation on apredetermined portion of the platen, first package element placementmeans for placing a base element on said package element holding meansat a first station, means for guiding the product into position on thebase element at a second station, second package element placement meansfor placing a cover element over the product and base at a thirdstation, a concave housing, means for moving said housing into sealingengagement with said platen surrounding said package element holdingmeans at a fourth station, whereby said housing cavity and said platendefine a package-accommodating vacuum chamber, means for applying avacuum to said vacuum chamber, an annular sealing member carried by saidhousing within said concavity, said sealing member being normally heldin an upwardly disposed retracted position, and power means for movingsaid sealing member downwardly toward said platen while said housing isin sealing engagement with said platen, whereby the peripheral portionsof said package elements may be forced into sealing engagement while avacuum is being applied to said chamber.
 12. The apparatus of claim 11and further including product alignment means intermediate said productguiding means and said cover placing means for aligning the product onthe base element.
 13. The apparatus of claim 11 wherein at least one ofsaid package element placement means includes means above said conveyorat the associated station for holding a stack of package elements, anarm mounted for movement relative to said frame and carrying packageelement attachment means for engaging and releasably attaching to thelowermost package element in the stack, means for moving said arm firstto effect removal of the attached package element from the stack andthen to effect movement of the package element onto said package elementholding means.
 14. The apparatus of claim 13 wherein said arm ispivotally mounted on said frame and is movable first radially inwardlyto effect removal of the attached package element, then is pivotallymoved to a position above said holding means and then is moved radiallyoutward to place the package element in said holding means.
 15. Theapparatus of claim 13 wherein said means carried by said arm forengaging and releasably attaching to the lowermost package element inthe stack is a resilient cup, and means is provided for drawing a vacuumwithin said cup when said cup is in engagement with the lowermostpackage element in the stack and for releasing the vacuum when thatpackage element has been moved onto said package element holding means.16. The apparatus of claim 12 wherein said product alignment meansincludes a subframE, at least two product engaging members mounted onsaid subframe for limited movement toward and away from each other, andmeans for moving said subframe from a raised position above said packageelement holding means to a lowered position within said package elementholding means whereby when said members are moved toward each other theywill engage and align the product on the base element within saidholding means.
 17. The apparatus of claim 12 wherein there are twopackage element holding means on each platen, and said product alignmentmeans includes a subframe, at least two sets of product alignment platescarried by said subframe, each set comprising two pairs of plates, theplates in each pair being substantially parallel and relatively movablewith respect to one another, the pairs of plates in each set beingdisposed substantially perpendicular with respect to one another, meansfor moving said subframe from a raised position above said packageelement holding means to a lowered position, and means for moving theplates in each set toward each other to substantially simultaneouslyengage and align the products on the base elements within said twopackage element holding means.
 18. The apparatus of claim 17 whereinsaid product alignment means includes two pairs of product engagingmembers, said pairs being mounted on said subframe for transversemovement with respect to each other, whereby the product may be alignedon four sides.
 19. The apparatus of claim 11 and further including meansfor removing the sealed package from said platen after said platen hasmoved from the sealing station.
 20. The apparatus of claim 19 whereinsaid means for removing the sealed package from said platen includes atleast one suction cup, means for moving said suction cup between twolocations, and means for applying a suction to said suction cup in onelocation and releasing it in the other location, whereby said suctioncup may attach to the package in said one location and the package maybe transported to and released in said other location.
 21. The apparatusof claim 19 wherein said means for removing the sealed package from saidplaten includes a support, an arm mounted on said support for pivotalmovement about a horizontal axis, package attachment means mounted onsaid arm for rotational movement about a horizontal axis, and means forrotating said package attachment means relative to said arm atsubstantially the same angular rate and in the opposite direction as thepivotal movement of said arm with respect to said support, whereby saidpackage attachment means will maintain substantially the sameorientation with respect to the horizontal throughout the pivotalmovement of said arm.
 22. The apparatus of claim 20 wherein said meansfor rotating said package attachment means relative to said arm includesa first pulley affixed to said support, a second pulley affixed to saidpackage attachment means, and an endless band encircling said pulleys.23. An apparatus for vacuum packaging of a product in a packageconsisting of two rigid package elements, said apparatus comprising aplurality of platens, means for moving said platens sequentially along apredetermined path through a plurality of operating stations, each ofsaid platens having package element holding means thereon adapted toreceive and hold the package elements in substantially alignedsuperposed relation on a predetermined portion of the platen, means forholding a supply stack of each of said preformed package elements andfor sequentially transferring said elements from the supply stacks tosaid platens at predetermined operating stations, a concave housing,means for moving said housing into sealing engagement with said platensurrounding said package element holding means after said packageelements have been positioned thereon, whereby said housing cavity andsaid platen define a package-accommodating vacuum chamber, means forapplying a vacuum to said vacuum chamber, an annular sealing mEmbercarried by said housing within said concavity, said sealing member beingnormally held in an upwardly disposed retracted position, and powermeans for moving said sealing member downwardly toward said platen whilesaid housing is in sealing engagement with said platen, whereby theperipheral portions of said package elements may be forced into sealingengagement while a vacuum is being applied to said chamber.
 24. Anapparatus for vacuum packaging of a product in a two element packageconsisting of a preformed relatively flat rigid base element and apreformed inwardly concave rigid cover element; said apparatuscomprising a plurality of platens, means adapted to move said platenssequentially along a predetermined path through a plurality of operatingstations, each of said platens having package element holding meansthereon adapted to receive and hold the package elements insubstantially aligned superposed relation on a predetermined portion ofthe platen, first package element placement means for placing one ofsaid elements on said package element holding means at a first station,means for guiding the product into position with respect to said oneelement at a second station, second package element placement means forplacing the other of said elements over the product and said one elementat a third station, a concave housing, means for moving said housinginto sealing engagement with said platen surrounding said packageelement holding means at a fourth station, whereby said housing cavityand said platen define a package-accommodating vacuum chamber, means forapplying a vacuum to said vacuum chamber, an annular sealing membercarried by said housing within said concavity, said sealing member beingnormally held in an upwardly disposed retracted position, and powermeans for moving said sealing member downwardly toward said platen whilesaid housing is in sealing engagement with said platen, whereby theperipheral portions of said package elements may be forced into sealingengagement while a vacuum is being applied to said chamber.
 25. Anapparatus for vacuum packaging of the product in a two element packageconsisting of a preformed rigid base element and a preformed rigid coverelement, said apparatus comprising at least one platen, a plurality ofmeans on said platen for holding the package elements in substantiallyaligned superposed relation on a predetermined portion of said platen,whereby a plurality of packages may be assembled and sealed on eachplaten simultaneously, a concave housing, means for moving said housinginto sealing engagement with said platen surrounding said holding means,whereby said housing concavity and said platen define apackage-accommodating vacuum chamber, means for applying a vacuum tosaid vacuum chamber, an annular sealing member carried by said housingwithin said concavity, said sealing member being normally held in anupwardly disposed retracted position, and power means for moving saidsealing member downwardly toward said platen while said housing is insealing engagement with said platen, whereby the peripheral portions ofsaid package elements may be forced into sealing engagement while avacuum is being applied to said chamber.